1. Combined Effect of Ferric Chloride and Mercuric Chloride on the Growth of Cyanobacteria Anacystis nidulans By Ted Handler, Farrell Parker, Alex Lewis, and Nick Reed

2. Dr. Lee H. Lee

3. Background Information Industry spills massive amounts of heavy metals such as mercury, selenium, ferric chloride, and mercuric chloride in our water supply. This study tests the effects of ferric and mercuric chloride on the growth of Anacystis nidulans as an indicator of life in our waters.

4. Anacystis nidulans Small Small Sensitive Sensitive Photosynthetic Photosynthetic Simple Simple Provide an indication of heavy metal pollution on metabolic activities of higher organisms in the ecosystem. Provide an indication of heavy metal pollution on metabolic activities of higher organisms in the ecosystem.

5. Toxicity of Mercury Mercury in any form is toxic. Toxic effects can result from vapor inhalation, ingestion, injection, or absorption through the skin. Hg accumulates mostly in the kidney, causing significant renal damage. Chronic exposure leads to accumulation within the brain, causing neurological symptoms and birth defects.

6. Iron as an Essential Micronutrient Mineral needed in small amounts for body to stay healthy. Mineral needed in small amounts for body to stay healthy. Found in meat, fish, and poultry. Found in meat, fish, and poultry. Functions in the transport and storage of oxygen. Functions in the transport and storage of oxygen. Involved in DNA synthesis and catecholamine metabolism. Involved in DNA synthesis and catecholamine metabolism.

7. Toxicity of Iron Toxicity most common in children. Toxicity most common in children. Toxicity occurs when free iron levels exceed the iron binding capacity of transferrin in blood. Toxicity occurs when free iron levels exceed the iron binding capacity of transferrin in blood. Free iron damages many organs by direct cellular toxicity. Free iron damages many organs by direct cellular toxicity.

8. Materials 4 Flasks 4 Flasks 4 Cuvettes 4 Cuvettes Disposable Pipettes Disposable Pipettes 5 mL sterile pipettes 5 mL sterile pipettes Cotton Cotton Cloth (breathable) Cloth (breathable) Foil Foil Tape Tape 3M Medium 3M Medium Cadmium and Ferric chloride Cadmium and Ferric chloride Hand Tally Counters Hand Tally Counters Microscope Microscope Micropipettes Micropipettes

9. Procedure We made a 3M medium for cell growth, using pipettes and micropipettes, and ten compounds. We made a 3M medium for cell growth, using pipettes and micropipettes, and ten compounds. We adjusted the pH to 7.95. We adjusted the pH to 7.95. We sterilized it by autoclaving the medium at 121° C. We sterilized it by autoclaving the medium at 121° C. We mixed the Anacystis nidulans with the medium. Then distributed it into 4 flasks. Each flask with 100mL of Anacystis nidulans culture. We mixed the Anacystis nidulans with the medium. Then distributed it into 4 flasks. Each flask with 100mL of Anacystis nidulans culture. 1 st flask had no heavy metals, this was our control. 1 st flask had no heavy metals, this was our control. 2 nd flask has 0.5 mg/L of HgCl 2 and 50 mg/L of FeCl 3. 2 nd flask has 0.5 mg/L of HgCl 2 and 50 mg/L of FeCl 3. 3 rd flask has 1 mg/L of HgCl 2 and 50 mg/L of FeCl 3. 3 rd flask has 1 mg/L of HgCl 2 and 50 mg/L of FeCl 3. 4 th flask has 5 mg/L of HgCl 2 and 50 mg/L of FeCl 3. 4 th flask has 5 mg/L of HgCl 2 and 50 mg/L of FeCl 3.

10. Procedure (cont’d) We used a micropipette to transfer HgCl 2 and FeCl 3 We used a micropipette to transfer HgCl 2 and FeCl 3 Then we observed the Anacystis nidulans every 3 or 4 days by two methods. Then we observed the Anacystis nidulans every 3 or 4 days by two methods. First, we used a spectrophotometer to measure absorbance levels at 750nm. First, we used a spectrophotometer to measure absorbance levels at 750nm. Second, we used hand tally counters to count the cells under a microscope, on a special slide called a hemacytometer, or a bacterial counting chamber. Second, we used hand tally counters to count the cells under a microscope, on a special slide called a hemacytometer, or a bacterial counting chamber.

11. Results: Control

12. Results: Flask 2

13. Results: Flask 3

14. Results: Flask 4

15. pH Results Day Flask #1 Flask #2 Flask #3 Flask #4 Day 1 7.957.957.957.95 Day 27 99.49.157.41

16. Conclusions After extensive growth of Anacystis nidulans in flasks 2 and 3, a resistance is built to the mercuric chloride and ferric chloride. The cyanobacteria thrives after growing a resistance and grows at a rate faster then that of the control. However, after a stationary point is reached at a high enough concentration, the cyanobacteria begin to die.

17. Conclusions (cont’d) In flask 4, the concentrations of the heavy metals were too high for the cyanobacteria to be able to resist it. The cyanobacteria had no chance to grow, and began to die very rapidly, from the beginning of the experiment.

18. Thank You!